The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingFront suspension lower no. 1 Arm
Components
Removal
Remove front wheel
Remove hood sub-assembly
Remove the hood (see page ed-4).
Suspend engine assembly
Install the no. 1 And no. 2 Engine hangers with the
bolts as shown in the illustration.
Torque: 38 n*m (387 kgf*cm, 28 ft.*Lbf)
parts no.
...
Disposal
Hint:
When scrapping a vehicle equipped with an srs or disposing
of the curtain shield airbag assembly, be sure to deploy the
airbag first in accordance with the procedure described
below. If any abnormality occurs with the airbag deployment,
contact the service dept. Of toyota motor sales,
u. ...
Reassembly
Install sliding roof drive cable
Using a screwdriver, slide the sliding roof drive
cable sub-assemblies in the direction indicated by
the arrow in the illustration to install them.
Hint:
Tape the screwdriver tip before use.
Engage the 2 claws and install the sliding roof ...